Frequent, low-severity fires were the norm in many dry forests across the western United States, prior to Euro-America settlement. These fires kept accumulated fuels such as fallen branches and dead trees to a minimum. They cleared out many younger, smaller trees while older trees in these fire-adapted ecosystems developed thick bark that protected them from the heat of periodic fires.
Roughly 60 percent of all houses built in the United States during 1990s were constructed within the wildland-urban interface. Having a national forest as one’s backyard can be enticing, but brings with it challenges for homeowners and public land managers. Fire is perhaps the biggest challenge. More than 140,000 wildfires occur on average each year and threaten homes that have been built in areas prone to frequent fires.